The Role
Design, build, and operate scalable distributed backend systems and services end to end. Integrate Web3 protocols, blockchain networks, and smart contracts while ensuring reliability, security, performance, observability, and code quality. Collaborate with product teams and API clients to shape solutions, contribute to technical discussions, mentor engineers, and use AI throughout the development workflow.
Summary Generated by Built In
We're looking for a Senior Backend Engineer to join our backend team at Zerion.
This team builds and evolves the backend systems at the core of our products and customer-facing solutions.
In this role, you'll design and operate distributed systems, work with Web3 infrastructure, and collaborate closely with product, support, and the clients building on our API to deliver reliable, scalable solutions.
We value strong ownership, thoughtful system design, and a high bar for code quality.
If you enjoy building solid systems, moving fast without cutting corners, and using AI as a core part of how you work, you'll feel right at home with us.
This team builds and evolves the backend systems at the core of our products and customer-facing solutions.
In this role, you'll design and operate distributed systems, work with Web3 infrastructure, and collaborate closely with product, support, and the clients building on our API to deliver reliable, scalable solutions.
We value strong ownership, thoughtful system design, and a high bar for code quality.
If you enjoy building solid systems, moving fast without cutting corners, and using AI as a core part of how you work, you'll feel right at home with us.
What You’ll Do
- Design, build, and maintain scalable distributed backend systems powering platform and product capabilities.
- Own backend services end-to-end: from architecture and implementation to monitoring and long-term reliability.
- Work closely with product and engineering peers to actively shape product decisions — not just execute specs.
- Scope solutions with the clients building on our API: turn a vague request into a concrete proposal, and the proposal into a plan the team can build.
- Build and evolve Web3 platform backend components, including protocol integrations, support for newly emerging blockchain networks, and reliable interactions with smart contracts.
- Ensure high standards of code quality, performance, security, and observability.
- Operate comfortably in a fast-paced startup environment, balancing speed and correctness.
- Use AI as a core part of your engineering workflow — designing, reviewing, debugging and shipping with it. This is how the team works day to day, not an experiment we're running.
- Contribute to technical discussions, reviews, and mentorship within the engineering team.
What We’re Looking For
- 5+ years of experience designing and building distributed backend systems.
- Strong knowledge of algorithms, data structures, and software design patterns.
- Comfortable working in a fast-paced startup environment.
- Strong desire to actively contribute to product evolution, not just implementation.
- Comfortable working directly with customers — hearing a vague problem and coming back with a concrete proposal.
- Hands-on, daily use of AI in your engineering work. You should be able to talk concretely about where it has changed how you build, and where you've learned not to trust it.
- High standards for code quality, system reliability, and user experience — you care about getting it right, not just getting it done.
- Strong ownership mindset — you take responsibility for outcomes, not just tasks.
- Clear and proactive communication in a distributed team.
- Pragmatic decision-making: knowing when to move fast vs. go deep.
- Ability to learn quickly and adapt.
Technical Skill Set
- Excellent knowledge of Golang is a plus, not a blocker.
- Experience with containerized systems: Docker & Kubernetes.
- Experience with databases:
- SQL: Postgres
- NoSQL: MongoDB, Cassandra
- Experience with monitoring and observability tools: Sentry, Prometheus, Grafana.
- Hands-on experience with AWS (Amazon Web Services).
- Experience with Python 3.
- Comfort experimenting with and integrating AI-assisted workflows into daily engineering work.
Bonus Points
- Hands-on Web3 experience: Blockchain systems, dApps, Smart contracts.
- Prior experience in a startup environment that emphasizes trust and autonomy.
- Located in time zones close to Europe for smoother collaboration.
- Collaborative mindset and respect for different perspectives.
- Curiosity and willingness to challenge existing solutions when better ones exist.
Interview Process
- Screening Call – 30 minutes
- Hiring Manager Interview – 45 minutes
- Technical Interview – 90 minutes (includes a real-world challenge where you'll work with AI tools directly)
- System Design Interview – 90 minutes
- Team Interview – 60 minutes
- Founders Call – up to 60 minutes
- Reference Check
We read every application in full before moving forward - as part of that, please include the word WATERMELON somewhere in your answer to the application question below
Why You Should Join
Why You Should Join
Company Overview
Zerion API
Trusted by 50+ top crypto and fintech brands
Powering 2k+ active clients monthly
Over 10B total requests processed
A lean, senior AI-native team shipping at outsized scale
Zerion Wallet
1.7M+ active funded wallets
27.6M+ transactions
2.5B+ transaction volume
416K+ unique holders of Zerion DNA NFT
Culture: Our culture shines through in our strong team engagement and impressive retention, showing just how much we value creating a workplace where people truly want to stay and thrive.
People: Collaborate with some of the most driven and intelligent individuals in the crypto space.
Salary & Benefits: Receive a competitive salary, medical insurance, coworking membership, and additional benefits.
Unlimited Days Off and Flexible Work Schedule: Recharge and explore life outside the office with our flexible time-off policy and work schedule.
Remote Work Essentials: We provide all the necessary software and equipment to ensure you're fully equipped to work from home comfortably and efficiently.
Stock Options: Contribute to Zerion's success and watch your stock options become valuable.
Travel: Connect with your teammates around the world at industry events and our annual team offsite.
Distributed Team: Zerion is a fully remote team with members worldwide. Embrace asynchronous collaboration, find your own work rhythm, and enjoy a healthy work-life balance.
To ALL recruitment agencies and individual recruiters: Zerion only accepts resumes from its partners, with whom Zerion has contractual relations. Zerion is not responsible for any fees or charges associated with unsolicited resumes.
Skills Required
- 5+ years of experience designing and building distributed backend systems
- Strong knowledge of algorithms, data structures, and software design patterns
- Experience with containerized systems using Docker and Kubernetes
- Experience with SQL databases, particularly PostgreSQL
- Experience with NoSQL databases, including MongoDB and Cassandra
- Experience with monitoring and observability tools such as Sentry, Prometheus, and Grafana
- Hands-on experience with AWS
- Experience with Python 3
- Daily hands-on use of AI in engineering work
- Ability to work directly with customers and turn vague problems into concrete proposals
- Clear, proactive communication and strong ownership in a distributed team
- Golang experience
- Hands-on Web3 experience with blockchain systems, dApps, or smart contracts
- Prior startup experience emphasizing trust and autonomy
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The Company
What We Do
At Zerion, we are on a mission to empower more people around the world with efficient, transparent, and censorship-resistant financial services. We do this by building applications, tools, and infrastructure enabling any smartphone holder, anywhere in the world, to build and manage their decentralized finance (DeFi) portfolios. The company was founded in 2016 by a technical team of crypto-native builders who sought to change the way centralized financial services work, primarily driven by experiencing the lack of financial opportunity within their countries. Zerion has grown to become one of the most popular DeFi interfaces in the world. Since inception, Zerion has processed over $1 billion in transaction volume and serves more than 200K monthly active users from over 150 countries. It has attracted significant investment from experienced investors such as Mosaic Ventures (investors in Alibaba Group and Pinterest), Lightspeed Ventures (investors in Snapchat), Placeholder Ventures, DeFi Alliance Fund, Continue Capital, DCG, and G1 Ventures amongst others. In 2019 and 2020, Zerion was awarded with the ‘best crypto UX/UI’ awards at DevCon Osaka 5 and London-based City AM’s inaugural Crypto AM awards respectively.
